AU2010200248A1 - Water Tank - Google Patents

Abstract

The present invention relates to a water tank 10. The water tank 10 has a plurality of independent walls 12, 14 arranged with an outer wall 14 nested about an innermost wall 12. The plurality of walls 12, 14 are spaced apart and separated by a volume 16 which acts as an insulation layer protecting the innermost wall 12. The water tank 10 also includes internal plumbing having a split level system for maintaining domestic and fire fighting water storage. A sprinkler system mounted to the roof 26 of the tank 10 reduces the risk of embers taking hold on or about the tank 10. 0h __ _ _ _ __0_ _ _ _ I.All

Description

AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT (Original) APPLICATION NO: LODGED: COMPLETE SPECIFICATION LODGED: ACCEPTED: PUBLISHED: RELATED ART: NAME OF APPLICANT: Rhino Water Tanks and Liners Pty Ltd ACTUAL INVENTOR: Harvey Durston ADDRESS FOR SERVICE: LORD AND COMPANY, Patent and Trade Mark Attorneys, of 4 Douro Place, West Perth, Western Australia, 6005, AUSTRALIA. INVENTION TITLE: "A WATER TANK" The following Statement is a full description of this invention including the best method of performing it known to us: TITLE "A WATER TANK" TECHNICAL FIELD The present invention relates to a water tank. BACKGROUND OF THE INVENTION Many water tanks cannot withstand the heat associated with a passing fire front and as such are unreliable when they are needed most. Plastic tanks and fittings are generally unsuitable in any fire event and many fire plans fail due to the melting of PVC and/or plastic pipe connections to fire fighting pumps which are exposed to the heat of the fire front. Traditional fire resistant tanks made from concrete are heavy and bulky making their transport, installation and maintenance expensive. Further, the fittings of such tanks are external leaving them unprotected in the event of a fire. 0 Other methods include mounting a water tank upon a raised platform. However, this incurs extra costs of additional platform materials and extended piping together with the extra steps of installation. A raised water tank also has further difficulties for access and maintenance. 5 2 Underground tanks may be suitable as a water tank in some situations, depending on the geological nature of the site however installation costs are greatly increased as is the time and effort involved in maintenance. The present invention attempts to overcome at least in part the aforementioned disadvantages of previous water tanks. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention there is provided a water tank having a wall means comprising an inner wall and an outer wall surrounding the inner wall wherein the inner wall and the outer wall are spaced apart so as to define a volume therebetween, and the wall means surrounds an internal space arranged to contain water . BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross sectional view of a water tank in accordance with the present 0 invention; Figure 2 is a side elevation view of the water tank of Figure 1; and Figure 3 is a plan view of the water tank of Figure 1. 5 3 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the Figure 1, there is shown a water tank 10, having tank wall means comprising a plurality of tank walls with an innermost wall 12 enclosing an internal tank space 17 and at least one outer wall 14 enclosing the innermost wall 12. The internal space 17 is defined by an inner surface 13 of the innermost wall 12, a ground floor 19 and a tank roof 26. In the preferred embodiment of the present invention the walls 12, 14 are substantially cylindrical in shape and are arranged concentrically about a substantially vertical centre axis (not shown) of the tank 10. It is to be understood that the tank 10 may also be arranged to assume other shapes as may be found suitable or desirable. It is also to be understood that the preferred embodiment of the present invention comprises two walls 12, 14. However other embodiments may comprise three or more walls. The tank walls 12, 14 are typically made from a treated steel based sheet material such as though not limited to corrugated zinc or powder coated. The tank roof 26 extends over the internal space 17 to at least the outer wall 14. In a preferred embodiment of the present invention the roof 26 having an outer surface 27 is generally domed or flat. The o roof 26 is constructed and reinforced by known means and made from the same or similar material as the tank walls 12, 14. As shown in Figure 1, the walls 12, 14 are spaced apart and volume 16 is defined there between. Thus, an outer surface 23 of the innermost wall 12 is separated and spaced 4 apart from an inner surface 25 of the outer wall 14. In a preferred embodiment of the present invention the sandwiched volume 16 comprises an annular ring arranged between the tank walls 12,14. The volume 16 act as an insulation means and is arranged to contain air though it is to be understood that other fire or heat resistant materials may be used to substantially fill or partially fill the volume 16. Further, a heat resistant membrane 18 is fitted between the innermost wall 12 and an internal waterproof lining 15. In the present embodiment the heat resistant membrane 18 spaces apart and separates the waterproof lining 15 from an inner surface 13 of the innermost wall 12. Typically, the heat resistant membrane lining 18 is made from a reinforced polyethylene material having a metallocene coating or other equivalent material having a high thermal stability in order to protect the waterproof lining 15 from radiated and convection heat in the event of a fire. As can be seen in Figure 2 the innermost wall 12 is arranged to be in communication with a plurality of horizontal structural reinforcement members 22 and vertical structural reinforcement members 20 as is known in the art. The outer wall 14 is arranged to encase the structural reinforcement members 20,22 and the innermost wall 12 thereby shielding the innermost wall 12 and reinforcement members 20, 22 and protecting the structural o integrity of the tank 10. Also seen in the water tank 10 of Figure 2 is a foundation bedding 24. Typically a water tank 10 in accordance with a preferred embodiment of the present invention will be mounted upon a prepared bed of sand or gravel as is known in the art. 5 In a preferred embodiment of the present invention the plumbing means is arranged to be internally mounted within the tank 10 internal space 17 and extend below into the foundation bedding 24. Typically, as shown in Figure 1, the plumbing means comprises a plurality of pipes 50, 52, 54 arranged to extend substantially upwardly into the internal tank space 17 from the foundation bedding 24 through the floor 19 of the tank 10 thereby passing through the internal waterproof tank liner 15. It is envisaged the plumbing means will provide a split level take off system having an upper intake 40 height HI and a lower intake 42 height H2 where the heights HI and H2 are measured upwardly from the tank floor 19. Typically, the upper intake 40 is arranged in fluid communication with the pipe 50 which is a domestic water supply pipe while the lower intake 42 may be in fluid communication with the pipe 52 which is a fire fighting water supply pipe. Similarly, it is envisaged that the pipe 54 will be an overflow riser pipe is to be plumbed internally rising through the floor 19 of the tank 10 to a predetermined overflow height H3 and arranged with a drainage outlet 44 to externally discharge excess water by gravity. It is envisaged that the pipes 50, 52 will be in fluid communication with at least one water 0 pump (not shown) as is known in the art. The lower intake 42 fire fighting water supply pipe 52 is arranged to be in fluid communication with an external fire coupling 48. In use, the external fire coupling 48 may be subsequently connected to suitable hosing (not shown) for quick and easy access to water in a fire event. 6 It is to be understood that a preferred arrangement of the present invention involves a plurality of water pumps (not shown) including a respective domestic water supply pump and a fire fighting water supply pump. Typically, the upper intake 40 would be arranged in fluid communication with the domestic water supply pump (not shown) and the lower intake 42 would be arranged in fluid communication with the fire fighting water supply pump (not shown). To ensure that a predetermined minimum quantity of water is available for use in fire fighting it is understood that the domestic water supply intake 40 height HI is plumbed to be greater than the fire fighting water supply intake 42 height H2. Further, in a preferred embodiment of the present invention the plumbing means also comprises an underground valve box 46 arranged to be externally accessible via a lid (not shown). It is to be understood that the valve box 46 and lid are made of a strong fire resistant material such as, for example, galvanised iron. Further, the pumps may be mounted in the underground valve box 46 or have provision for some other protective means such as, for example, a separate pump shed. In a preferred embodiment of the present invention the pipe 50 also comprises a o galvanised riser pipe 47 allowing external access to the fire supply pipe 50 and the lower level take off point 42. Typically, the galvanised riser pipe 47 will be fitted with the appropriate fire coupling 48 and arranged to stand at a suitable height and position for the quick, easy and secure attachment of fire fighting hosing (not shown). 7 In the preferred embodiment of the water tank 10 of the present invention comprises a roof mounted sprinkler system. At least a single sprinkler is mounted to the roof 26 and internally plumbed so that the sprinkler piping (not shown) is shielded from the heat of a fire. It is to be understood that the sprinkler system design is matched to the size of the tank 10 so that the roof 26 and external tank wall 14 are cooled thereby in the event of a fire reducing the radiated heat and extinguishing any embers on the roof 26. Further, embers from a fire are unable to ignite around the tank 10 the sprinkler water will be arranged to create a moisture barrier about an external perimeter of the tank 10. In a preferred embodiment of the present invention it is envisaged the internal waterproof liner 15 will be arranged about the tank ground floor 19 and internal surface 13 of the inner tank wall 12 thereby waterproofing the internal tank space 17. The internal waterproof liner 15 is to be made from a suitable food grade plastic material as is known in the art. In use, an operator may use the tank 10 for domestic water supply supplied by a primary water pump as is known in the art. Upon a pending or approaching fire threat the operator may access the valve box 46 and open the appropriate valves before activating a o secondary fire pump. The operator then connects appropriate hosing to the galvanised riser 47 fire coupling 48 and uses the water to dampen the surrounding areas, to fight and/or to extinguish the fire. Simultaneously, the roof-mounted sprinkler system maybe activated thereby cooling the tank roof 26 and outer wall 14 as well as providing a moisture barrier about the tank perimeter including the valve box 46 and galvanised riser 8 47 and fire coupling 48. As a fire front nears the water tank 10 of the present invention the path of the fire is typically slowed by the moisture barrier created by the roof mounted sprinkler system. Further, the innermost tank wall 12 and structural members 22, 20 are protected against flames, radiant heat and embers of a fire front as it passes. The transfer of heat from the external wall 14 to the innermost wall 12 is resisted by the air filled annular ring 16 separating the two walls 12, 14 thereby insulating the innermost wall 12. The membrane lining 18 about the internal surface 13 of the innermost wall 12 protects the waterproof lining 15 from any radiant or convective heat transfer ensuring the tanks 10 capacity to hold water. The water tank 10 piping comprising the domestic supply pipe 50, the fire fighting supply pipe 52, the overflow pipe 54 and the sprinkler system piping (not shown) are all internally and subterraneously plumbed thereby being at all times protected from the direct heat of a fire and accordingly not compromised by heat related damage. This ensures the reliability of the both the domestic and fire fighting water supplies together with the sprinkler system. o Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. 9

Claims (10)

1. A water tank having a wall means comprising an inner wall and an outer wall surrounding the inner wall wherein the inner wall and the outer wall are spaced apart so as to define a volume therebetween, and the wall means surrounds an internal space arranged to contain water.

2. A water tank in accordance with claim 1, wherein the internal space is lined with a waterproof liner.

3. A water tank in accordance with claim 2, wherein a heat resistant membrane is disposed between the inner wall and the liner.

4. A water tank in accordance with claim 3, wherein the volume contains air.

5. A water tank in accordance with any one of the preceding claims, which comprises a roof over the internal space and a floor below the internal space. 0

6. A water tank in accordance with claim 5, wherein the tank comprises plumbing means having at least a domestic water supply outlet pipe, a fire fighting water supply outlet pipe, and an overflow water outlet pipe 10

7. A water tank in accordance with claim 6, wherein each respective pipe has an independent intake height and is independently and internally plumbed through the tank floor, wherein the height of the domestic water supply intake is greater than the height of the fire fighting water supply intake.

8. A water tank in accordance with the claim 6 or 7, wherein the tank has provision for a roof mounted sprinkler system, wherein at least one sprinkler outlet is mounted to the roof of the tank and arranged, in use, to spray at least an outer surface of the roof of the tank.

9. A water tank in accordance with claim 8, wherein the roof mounted sprinkler system is supplied with water from the fire fighting water supply pipe.

10. A water tank in accordance with claim 10, wherein plumbing for the roof mounted sprinkler is internally mounted. 0 11